Perylene diimide (PDI) derivatives hold great promise as stable, solution‐printable n‐type organic thermoelectric materials, but as of yet lack sufficient electrical conductivity to warrant further development. Hybrid PDI‐inorganic nanomaterials have the potential to leverage these physical advantages while simultaneously achieving higher thermoelectric performance. However, lack of molecular level insight precludes design of high performing PDI‐based hybrid thermoelectrics. Herein, the first explicit crystal structure of these materials is reported, providing previously inaccessible insight into the relationship between their structure and thermoelectric properties. Allowing this molecular level insight to drive novel methodologies, simple solution‐based techniques to prepare PDI hybrid thermoelectric inks with up to 20‐fold enhancement in thermoelectric power factor over the pristine molecule (up to 17.5 µW mK−2) is presented. This improved transport is associated with reorganization of organic molecules on the surface of inorganic nanostructures. Additionally, outstanding mechanical flexibility is demonstrated by fabricating solution‐printed thermoelectric modules with innovative folded geometries. This work provides the first direct evidence that packing/organization of organic molecules on inorganic nanosurfaces is the key to effective thermoelectric transport in nanohybrid systems.
Soft thermoelectric materials, including conjugated polymers and organic–inorganic hybrids, now demonstrate figures of merit approaching those of inorganic materials. These materials development breakthroughs enable the design of thermoelectric devices that exhibit appropriate efficiencies for commercial use, while simultaneously leveraging the unique processing and mechanical advantages of soft materials. Such a technology opens the door to a suite of new thermoelectric applications, including power generation for biomedical implants and the Internet of Things, or wearable heating and cooling devices. In order to realize deployment of such technologies, there is a fundamental need for deeper understanding of the complex transport physics underlying thermoelectric transport in soft materials. Here, the current state of the art in soft thermoelectrics materials is discussed, and outstanding challenges specific to organic and organic–inorganic hybrid systems are highlighted.
more » « less- NSF-PAR ID:
- 10460398
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Electronic Materials
- Volume:
- 5
- Issue:
- 11
- ISSN:
- 2199-160X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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